水稻多效性基因Ghd7.1的克隆与功能分析
发布时间：2018-08-03 21:07
【摘要】：水稻是我国的主要粮食作物之一,高产和稳产一直是水稻科技人员的主要追求目标。利用图位克隆的方法鉴定水稻高产基因,不仅可以解析水稻产量构成机制,还可以直接指导水稻分子设计育种。水稻是典型的短日照植物,以13.5h为临界点,在日照长度短于13.5h时提前开花,长于13.5h时延迟开花。前期利用汕优63的母本珍汕97与高产品种特青构建重组自交系,在该自交系中检测到一个可以同时延迟抽穗,增加株高和产量的多效性位点,该位点位于第7染色体末端,故将其命名为Ghd7.1(grain number,plant height and heading date)。本研究通过构建珍汕97为受体/特青为供体的Ghd7.1近等基因系,对Ghd7.1的表型进行了确认:特青等位基因型为显性,长日照条件下,表现为延迟抽穗19天,增加株高28cm,增产幅度超过60%。通过8h,10h和自然长日照条件下种植近等基因系并考察表型,发现Ghd7.1是一个光周期敏感的抽穗期基因,仅在长日照条件下抑制抽穗期,短日照条件下无抽穗期表型差异,但是有微弱的株高和产量的表型差异。主茎穗考种显示株高增加是因为在特青等位基因型中茎节增加一节,同时每个茎节长度也显著长于珍汕97等位基因型对应的的茎节长度。对主茎穗的穗长、一次枝梗,二次枝梗和每穗颖花数等性状进行考察,发现特青等位基因型在上述性状也都显著增加,最终导致产量大幅度提高。在组织水平,通过对近等基因系幼穗进行动态观察,比较两种等位基因型的分化历时和分化速率,发现Ghd7.1是通过延长分化历时增加每穗颖花数。利用图位克隆的方法对该基因进行了克隆,发现Ghd7.1编码一个PRR(PSEUDO-RESPONSE REGULATORS)类的蛋白,具有一个REC domain(response receivers domain)和一个CCT domain(CONSTANS,CO-like,and TOC1domain),亚细胞定位显示Ghd7.1定位于细胞核。在拟南芥中,Ghd7.1的同源基因AtPRR7是生物钟核心振荡器的组份之一,通过生物钟来调控开花。而对Ghd7.1的近等基因系进行光周期处理,发现Ghd7.1并不影响水稻生物钟,而是通过抑制水稻特有的基因Ehd1来调控水稻抽穗期。通过对178份种质资源品种的重测序我们一共鉴定出24种等位基因型,结合关联分析共鉴定出7种无功能的等位基因型。粳稻中最主要的等位基因型是日本晴等位基因型,利用近等基因系进行了不同等位基因的效应评价,发现与特青等位基因型相比,日本晴等位基因型是一种弱等位基因型。进一步通过对47份野生稻的比较测序,未检测到无功能的等位基因型,暗示Ghd7.1是一个在水稻驯化中被保留下来的基因,并且籼稻和粳稻的主要基因型都可以在野生稻中找到序列完全一致的基因型,推断Ghd7.1籼稻和粳稻的等位基因型是独立起源于野生稻。进一步构建Ghd7.1序列上的进化流程图,发现其在水稻适应性和扩散过程中的重要贡献:Ghd7.1由野生稻的有功能到栽培稻的无功能等位基因型的进化历程,正是水稻能够由低纬度向高纬度扩散的重要推动力,同时通过Ghd7.1功能缺失后抽穗期短,育种家培育出生育期很短的品种在部分地区种植双季稻,提高农田利用效率。
[Abstract]:Rice is one of the main grain crops in China. High yield and stable yield have always been the main pursuit of rice science and technology personnel. The identification of high yield gene of rice by the method of map cloning can not only analyze the mechanism of rice yield, but also direct the rice molecular design and breeding. Rice is a typical short day plant with 13.5h as the critical point. When the length of sunshine is shorter than 13.5h, it blooms ahead of time and delays flowering when it is longer than 13.5h. In the early stage, a recombinant inbred line was constructed with the mother of Shanyou 63, the mother of Shanyou 97 and the high yield variety special green. In the inbred line, a pleiotropic location that could delay the heading, increase plant height and yield was detected at the end of the seventh chromosome. Ghd7.1 (grain number, plant height and heading date). In this study, the phenotype of Ghd7.1 was confirmed by constructing a Ghd7.1 near isogenic line with a receptor / special green as a donor. The special green allele was dominant. Under long sunshine conditions, the phenotype was delayed for 19 days and increased the plant height, and the increase of yield was more than that of 60%.. It is found that Ghd7.1 is a photoperiod sensitive gene of heading stage, which is a photoperiod sensitive gene, which only inhibits heading stage under long sunshine conditions and has no heading phase difference under short sunshine conditions, but there is a weak phenotype difference between plant height and yield. In the green allele, the stem node was increased by one node, and the length of each stem segment was significantly longer than that of the Jen Shan 97 allele. The spike length of the main stem, the primary branch, the two branch and the spikelet number per panicle were investigated. It was found that the special green allele also increased significantly in the above characters, which eventually led to a large yield. At the organizational level, the differentiation diachronic time and differentiation rate of the two alleles were compared by the dynamic observation of the near isogenic lines, and the number of spikelet number per panicle was increased by prolonging the differentiation period. The gene was cloned by the method of graph cloning, and Ghd7.1 was found to encode a PRR (PSEUDO-RESPONSE REGULA). TORS) proteins that have a REC domain (response receivers domain) and a CCT domain (CONSTANS, CO-like, and TOC1domain), which are located in the nucleus. In Arabidopsis, the homologous gene is one of the components of the core oscillator in the biological clock. The near isogenic lines were treated with photoperiod. It was found that Ghd7.1 did not affect the rice biological clock, but by inhibiting rice specific gene Ehd1 to regulate the heading stage of rice. By resequencing 178 germplasm resources, we identified 24 alleles, and identified 7 non functional allelic genotypes combined with correlation analysis. The main allele of the rice is the Japanese clear allele, and the effect of different alleles is evaluated using the near isogenic lines. It is found that the Japanese clear allele is a weak allele compared with the special green allele, and the non functional allele is not detected by the comparison of 47 wild rice sequences. Type, suggesting that Ghd7.1 is a gene preserved in rice domestication, and the major genotypes of both indica and japonica rice can be found in wild rice with a complete sequence of genotypes. It is concluded that the allelic genotypes of Ghd7.1 indica and japonica are independently derived from wild rice. The evolutionary flow chart of the Ghd7.1 sequence is constructed step by step. The important contribution in the process of rice adaptation and diffusion: the evolutionary course of Ghd7.1 from the functional to the non functional allele of cultivated rice is the important driving force for rice to spread from low latitudes to high latitudes. At the same time, the breeders cultivate short breeds at birth by the lack of Ghd7.1 function. Double cropping rice is planted in different regions to improve the efficiency of farmland utilization.
【学位授予单位】：华中农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S511;Q943.2
本文编号：2162999
[Abstract]:Rice is one of the main grain crops in China. High yield and stable yield have always been the main pursuit of rice science and technology personnel. The identification of high yield gene of rice by the method of map cloning can not only analyze the mechanism of rice yield, but also direct the rice molecular design and breeding. Rice is a typical short day plant with 13.5h as the critical point. When the length of sunshine is shorter than 13.5h, it blooms ahead of time and delays flowering when it is longer than 13.5h. In the early stage, a recombinant inbred line was constructed with the mother of Shanyou 63, the mother of Shanyou 97 and the high yield variety special green. In the inbred line, a pleiotropic location that could delay the heading, increase plant height and yield was detected at the end of the seventh chromosome. Ghd7.1 (grain number, plant height and heading date). In this study, the phenotype of Ghd7.1 was confirmed by constructing a Ghd7.1 near isogenic line with a receptor / special green as a donor. The special green allele was dominant. Under long sunshine conditions, the phenotype was delayed for 19 days and increased the plant height, and the increase of yield was more than that of 60%.. It is found that Ghd7.1 is a photoperiod sensitive gene of heading stage, which is a photoperiod sensitive gene, which only inhibits heading stage under long sunshine conditions and has no heading phase difference under short sunshine conditions, but there is a weak phenotype difference between plant height and yield. In the green allele, the stem node was increased by one node, and the length of each stem segment was significantly longer than that of the Jen Shan 97 allele. The spike length of the main stem, the primary branch, the two branch and the spikelet number per panicle were investigated. It was found that the special green allele also increased significantly in the above characters, which eventually led to a large yield. At the organizational level, the differentiation diachronic time and differentiation rate of the two alleles were compared by the dynamic observation of the near isogenic lines, and the number of spikelet number per panicle was increased by prolonging the differentiation period. The gene was cloned by the method of graph cloning, and Ghd7.1 was found to encode a PRR (PSEUDO-RESPONSE REGULA). TORS) proteins that have a REC domain (response receivers domain) and a CCT domain (CONSTANS, CO-like, and TOC1domain), which are located in the nucleus. In Arabidopsis, the homologous gene is one of the components of the core oscillator in the biological clock. The near isogenic lines were treated with photoperiod. It was found that Ghd7.1 did not affect the rice biological clock, but by inhibiting rice specific gene Ehd1 to regulate the heading stage of rice. By resequencing 178 germplasm resources, we identified 24 alleles, and identified 7 non functional allelic genotypes combined with correlation analysis. The main allele of the rice is the Japanese clear allele, and the effect of different alleles is evaluated using the near isogenic lines. It is found that the Japanese clear allele is a weak allele compared with the special green allele, and the non functional allele is not detected by the comparison of 47 wild rice sequences. Type, suggesting that Ghd7.1 is a gene preserved in rice domestication, and the major genotypes of both indica and japonica rice can be found in wild rice with a complete sequence of genotypes. It is concluded that the allelic genotypes of Ghd7.1 indica and japonica are independently derived from wild rice. The evolutionary flow chart of the Ghd7.1 sequence is constructed step by step. The important contribution in the process of rice adaptation and diffusion: the evolutionary course of Ghd7.1 from the functional to the non functional allele of cultivated rice is the important driving force for rice to spread from low latitudes to high latitudes. At the same time, the breeders cultivate short breeds at birth by the lack of Ghd7.1 function. Double cropping rice is planted in different regions to improve the efficiency of farmland utilization.
【学位授予单位】：华中农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S511;Q943.2
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